Russian officials earlier described the attacks as deliberate acts by pro-Chechen criminals and said an investigation was under way.

The electricity transmission line in Russia's southern region of Karachayevo-Cherkessiya - also near the Georgian border - was brought down by an explosion just hours later.

Saakashvili blames Russia

Relations between Georgia and Russia have been tense since Mr Saakashvili was swept to power by the so-called "Rose Revolution" in 2003, pledging to lead his nation on a pro-Western course.

Two explosions occurred on the main branch and a reserve branch of the Mozdok-Tbilisi gas pipeline in North Ossetia at about 0300 local time (2400 GMT) on Sunday.

Georgia is suffering from chronic shortages of gas

President Saakashvili's chief of staff, Georgi Arveladze, said it would take several days to resume gas supplies nationwide.

Mr Saakashvili said the blasts "happened at the same time, and basically they didn't affect supplies to Russia proper, so we can conclude that it was a very well-organised and very well co-ordinated act".

"We've received numerous threats by Russian politicians and officials at different levels to punish us for basically for not giving them pipelines."

He likened the crisis to Russia's recent gas showdown with Ukraine - another western-leaning former Soviet republic.

Extra gas

A senior executive at Russian gas giant Gazprom, Sergei Kupriyanov, told the BBC that an extra three million cubic metres of gas had been sent to Georgia via Azerbaijan.

He said repairs to the pipelines were being hampered by the fact that they were located in a remote mountainous area.

Georgia is holding emergency talks on energy supplies with Azerbaijan and Turkey.

Mr Saakashvili said Georgia must continue working to reduce its reliance on energy supplies from Russia.

The gas shortage led to long queues for gas canisters in Tbilisi and the temporary closure of schools.

Some Georgians have been turning to alternative heating, such as kerosene and wood-burning stoves, as they struggle to cope with one of their coldest winters for years.

Tbilisi's relations with Moscow have been soured by a continuing pro-Russian rebellion in Georgia's South Ossetia region, the closure of Russian bases in Georgia and the development of close Georgian-US military ties.